/* * Copyright 2015 Maxime Ripard * * Maxime Ripard * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. */ #include #include #include #include #include #define TCON_CH1_SCLK2_PARENTS 4 #define TCON_CH1_SCLK2_GATE_BIT BIT(31) #define TCON_CH1_SCLK2_MUX_MASK 3 #define TCON_CH1_SCLK2_MUX_SHIFT 24 #define TCON_CH1_SCLK2_DIV_MASK 0xf #define TCON_CH1_SCLK2_DIV_SHIFT 0 #define TCON_CH1_SCLK1_GATE_BIT BIT(15) #define TCON_CH1_SCLK1_HALF_BIT BIT(11) struct tcon_ch1_clk { struct clk_hw hw; spinlock_t lock; void __iomem *reg; }; #define hw_to_tclk(hw) container_of(hw, struct tcon_ch1_clk, hw) static void tcon_ch1_disable(struct clk_hw *hw) { struct tcon_ch1_clk *tclk = hw_to_tclk(hw); unsigned long flags; u32 reg; spin_lock_irqsave(&tclk->lock, flags); reg = readl(tclk->reg); reg &= ~(TCON_CH1_SCLK2_GATE_BIT | TCON_CH1_SCLK1_GATE_BIT); writel(reg, tclk->reg); spin_unlock_irqrestore(&tclk->lock, flags); } static int tcon_ch1_enable(struct clk_hw *hw) { struct tcon_ch1_clk *tclk = hw_to_tclk(hw); unsigned long flags; u32 reg; spin_lock_irqsave(&tclk->lock, flags); reg = readl(tclk->reg); reg |= TCON_CH1_SCLK2_GATE_BIT | TCON_CH1_SCLK1_GATE_BIT; writel(reg, tclk->reg); spin_unlock_irqrestore(&tclk->lock, flags); return 0; } static int tcon_ch1_is_enabled(struct clk_hw *hw) { struct tcon_ch1_clk *tclk = hw_to_tclk(hw); u32 reg; reg = readl(tclk->reg); return reg & (TCON_CH1_SCLK2_GATE_BIT | TCON_CH1_SCLK1_GATE_BIT); } static u8 tcon_ch1_get_parent(struct clk_hw *hw) { struct tcon_ch1_clk *tclk = hw_to_tclk(hw); u32 reg; reg = readl(tclk->reg) >> TCON_CH1_SCLK2_MUX_SHIFT; reg &= reg >> TCON_CH1_SCLK2_MUX_MASK; return reg; } static int tcon_ch1_set_parent(struct clk_hw *hw, u8 index) { struct tcon_ch1_clk *tclk = hw_to_tclk(hw); unsigned long flags; u32 reg; spin_lock_irqsave(&tclk->lock, flags); reg = readl(tclk->reg); reg &= ~(TCON_CH1_SCLK2_MUX_MASK << TCON_CH1_SCLK2_MUX_SHIFT); reg |= index << TCON_CH1_SCLK2_MUX_SHIFT; writel(reg, tclk->reg); spin_unlock_irqrestore(&tclk->lock, flags); return 0; }; static unsigned long tcon_ch1_calc_divider(unsigned long rate, unsigned long parent_rate, u8 *div, bool *half) { unsigned long best_rate = 0; u8 best_m = 0, m; bool is_double; for (m = 1; m < 16; m++) { u8 d; for (d = 1; d < 3; d++) { unsigned long tmp_rate; tmp_rate = parent_rate / m / d; if (tmp_rate > rate) continue; if (!best_rate || (rate - tmp_rate) < (rate - best_rate)) { best_rate = tmp_rate; best_m = m; is_double = d; } } } if (div && half) { *div = best_m; *half = is_double; } return best_rate; } static int tcon_ch1_determine_rate(struct clk_hw *hw, struct clk_rate_request *req) { long best_rate = -EINVAL; int i; for (i = 0; i < clk_hw_get_num_parents(hw); i++) { unsigned long parent_rate; unsigned long tmp_rate; struct clk_hw *parent; parent = clk_hw_get_parent_by_index(hw, i); if (!parent) continue; parent_rate = clk_hw_get_rate(parent); tmp_rate = tcon_ch1_calc_divider(req->rate, parent_rate, NULL, NULL); if (best_rate < 0 || (req->rate - tmp_rate) < (req->rate - best_rate)) { best_rate = tmp_rate; req->best_parent_rate = parent_rate; req->best_parent_hw = parent; } } if (best_rate < 0) return best_rate; req->rate = best_rate; return 0; } static unsigned long tcon_ch1_recalc_rate(struct clk_hw *hw, unsigned long parent_rate) { struct tcon_ch1_clk *tclk = hw_to_tclk(hw); u32 reg; reg = readl(tclk->reg); parent_rate /= (reg & TCON_CH1_SCLK2_DIV_MASK) + 1; if (reg & TCON_CH1_SCLK1_HALF_BIT) parent_rate /= 2; return parent_rate; } static int tcon_ch1_set_rate(struct clk_hw *hw, unsigned long rate, unsigned long parent_rate) { struct tcon_ch1_clk *tclk = hw_to_tclk(hw); unsigned long flags; bool half; u8 div_m; u32 reg; tcon_ch1_calc_divider(rate, parent_rate, &div_m, &half); spin_lock_irqsave(&tclk->lock, flags); reg = readl(tclk->reg); reg &= ~(TCON_CH1_SCLK2_DIV_MASK | TCON_CH1_SCLK1_HALF_BIT); reg |= (div_m - 1) & TCON_CH1_SCLK2_DIV_MASK; if (half) reg |= TCON_CH1_SCLK1_HALF_BIT; writel(reg, tclk->reg); spin_unlock_irqrestore(&tclk->lock, flags); return 0; } static const struct clk_ops tcon_ch1_ops = { .disable = tcon_ch1_disable, .enable = tcon_ch1_enable, .is_enabled = tcon_ch1_is_enabled, .get_parent = tcon_ch1_get_parent, .set_parent = tcon_ch1_set_parent, .determine_rate = tcon_ch1_determine_rate, .recalc_rate = tcon_ch1_recalc_rate, .set_rate = tcon_ch1_set_rate, }; static void __init tcon_ch1_setup(struct device_node *node) { const char *parents[TCON_CH1_SCLK2_PARENTS]; const char *clk_name = node->name; struct clk_init_data init; struct tcon_ch1_clk *tclk; struct resource res; struct clk *clk; void __iomem *reg; int ret; of_property_read_string(node, "clock-output-names", &clk_name); reg = of_io_request_and_map(node, 0, of_node_full_name(node)); if (IS_ERR(reg)) { pr_err("%s: Could not map the clock registers\n", clk_name); return; } ret = of_clk_parent_fill(node, parents, TCON_CH1_SCLK2_PARENTS); if (ret != TCON_CH1_SCLK2_PARENTS) { pr_err("%s Could not retrieve the parents\n", clk_name); goto err_unmap; } tclk = kzalloc(sizeof(*tclk), GFP_KERNEL); if (!tclk) goto err_unmap; init.name = clk_name; init.ops = &tcon_ch1_ops; init.parent_names = parents; init.num_parents = TCON_CH1_SCLK2_PARENTS; init.flags = CLK_SET_RATE_PARENT; tclk->reg = reg; tclk->hw.init = &init; spin_lock_init(&tclk->lock); clk = clk_register(NULL, &tclk->hw); if (IS_ERR(clk)) { pr_err("%s: Couldn't register the clock\n", clk_name); goto err_free_data; } ret = of_clk_add_provider(node, of_clk_src_simple_get, clk); if (ret) { pr_err("%s: Couldn't register our clock provider\n", clk_name); goto err_unregister_clk; } return; err_unregister_clk: clk_unregister(clk); err_free_data: kfree(tclk); err_unmap: iounmap(reg); of_address_to_resource(node, 0, &res); release_mem_region(res.start, resource_size(&res)); } CLK_OF_DECLARE(tcon_ch1, "allwinner,sun4i-a10-tcon-ch1-clk", tcon_ch1_setup);